Vehicle front suspension

ABSTRACT

A vehicle front suspension includes a lower suspension support structure, a transverse link, a steering knuckle and a lower knuckle breakaway structure. The transverse link has an inboard side and an outboard side, with the inboard side being attached to the lower suspension support structure. The steering knuckle is pivotally coupled to the outboard side of the transverse link. The lower knuckle breakaway structure is formed on one of the transverse link and the steering knuckle to release the steering knuckle from the transverse link upon application of a prescribed rearward directed force on the vehicle front suspension outboard of the lower suspension support structure.

BACKGROUND

1. Field of the Invention

The present invention generally relates to a vehicle front suspension.More specifically, the present invention relates to a vehicle frontsuspension that includes at least one breakaway structure thatfacilitates release of a front wheel in response to an impact event in afrontal offset test.

2. Background Information

Vehicle body structures are regularly being redesigned to includestructural features that absorb impact forces in response to impactevents. Recently introduced impact event tests include a frontal offsettest where a vehicle is provided with velocity in a vehicle longitudinaldirection (forward momentum) such that a front corner of the vehicle(approximately 25 percent of the overall width of the vehicle) impacts afixed, rigid barrier. FIGS. 1, 2 and 3 schematically show an example ofa conventional vehicle V undergoing an impact event with a fixed barrierB in accordance with the frontal offset test.

FIG. 1 shows the conventional vehicle V approaching the rigid barrier Bin the frontal offset test. FIG. 2 shows the conventional vehicle V justafter initial impact with the rigid barrier B showing initialdeformation and forward momentum being transformed into rotationaldisplacement about the rigid barrier B. FIG. 3 shows the conventionalvehicle V undergoing further deformation and rotation as a result of theimpact event.

SUMMARY

One object is to provide breakaway structures that release a wheel ofthe vehicle such that the wheel moves out of a vehicle wheel well duringan impact event of a frontal offset test.

In view of the state of the known technology, one aspect of the presentdisclosure is to provide a vehicle front suspension with a lowersuspension support structure, a transverse link, a steering knuckle anda lower knuckle breakaway structure. The transverse link has an inboardside and an outboard side, with the inboard side being attached to thelower suspension support structure. The steering knuckle is pivotallycoupled to the outboard side of the transverse link. The lower knucklebreakaway structure is formed on one of the transverse link and thesteering knuckle to release the steering knuckle from the transverselink upon application of a prescribed rearward directed force on thevehicle front suspension outboard of the lower suspension supportstructure.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure.

FIG. 1 is a schematic view of a conventional moving vehicle showing itsresponse to a small overlap test where a front corner of the vehicle isaligned with a fixed, rigid barrier for eventual impact with thebarrier;

FIG. 2 is another schematic view of the conventional vehicle showing itsresponse to the small overlap test at the beginning of an impact eventwith the front corner of the conventional vehicle impacting the barrierand beginning to undergo deformation;

FIG. 3 is still another schematic view of the conventional vehicleshowing its response to the small overlap test with the conventionalvehicle undergoing further deformation during the impact event;

FIG. 4 is a schematic view of a moving vehicle being subjected to asmall overlap test where approximately 25 percent of the front of thevehicle aligned with a fixed, rigid barrier for eventual impact with thebarrier in accordance with various embodiments;

FIG. 5 is another schematic view of the vehicle depicted in FIG. 4showing an initial response to the impact event of the small overlaptest with a front corner of the vehicle impacting the barrier andbeginning to undergo deformation in accordance with the variousembodiments;

FIG. 6 is still another schematic view of the vehicle depicted in FIGS.4 and 5 showing a subsequent response to the impact event of the smalloverlap test with the moving vehicle undergoing further deformationduring the impact event and with a front wheel moving laterally out of awheel well of the vehicle in accordance with at least one embodiment;

FIG. 7 is side view of a front end of the vehicle showing portions of afront suspension in accordance with a first embodiment;

FIG. 8 is a top view of portions of the front suspension of the vehicledepicted in FIG. 7, with the front suspension removed from the vehicleshowing an engine cradle, steering components, struts, steering knucklesand transverse links, the front suspension having a plurality of wheelreleasing features, including an upper knuckle breakaway structure, alower knuckle breakaway structure and a transverse link breakawaystructure, in accordance with a first embodiment;

FIG. 9 is a perspective view of the portions of the front suspension ofthe vehicle depicted in FIG. 8, showing the engine cradle, the struts,the steering knuckles and the transverse links in accordance with thefirst embodiment;

FIG. 10 is an exploded perspective view of the portions of the frontsuspension of the vehicle depicted in FIGS. 8 and 9, showing the enginecradle, a strut, a steering knuckle and a transverse link in accordancewith the first embodiment;

FIG. 11 is an exploded perspective view of the strut and the steeringknuckle of the front suspension showing an upper knuckle breakawaystructure in accordance with the first embodiment;

FIG. 12 is a side view of a lower end of the strut showing details ofknuckle attachment flanges that include the upper knuckle breakawaystructure in accordance with the first embodiment;

FIG. 13 is a perspective view of the strut and the steering knuckle ofthe front suspension fully assembled showing the upper knuckle breakawaystructure in accordance with the first embodiment;

FIG. 14 is a perspective view of the strut and the steering knuckle ofthe front suspension showing the upper knuckle breakaway structure afteran impact event releasing the steering knuckle from the lower end of thestrut in accordance with the first embodiment;

FIG. 15 is an exploded perspective view of the steering knuckle and anoutboard end of the transverse link of the front suspension showing alower knuckle breakaway structure in accordance with the firstembodiment;

FIG. 16 is a side view of a lower end of the steering knuckle showingdetails of the lower knuckle breakaway structure in accordance with thefirst embodiment;

FIG. 17 is a perspective view of the steering knuckle and the transverselink of the front suspension showing the lower knuckle breakawaystructure after an impact event releasing the steering knuckle from theoutboard end of the strut in accordance with the first embodiment;

FIG. 18 is a perspective view of the transverse link shown removed fromthe front suspension, the transverse link having an inboard side with afront attachment point and a rear attachment point, and an outboard sidein accordance with the first embodiment;

FIG. 19 is a top view of the front suspension showing the frontattachment point and the rear attachment point of the inboard side ofthe transverse link connected to the engine cradle defining a transverselink breakaway structure in accordance with the first embodiment;

FIG. 20 is another top view of the front suspension showing the frontattachment point of the transverse link breaking away from the enginecradle in an initial response to the impact event in accordance with thefirst embodiment;

FIG. 21 is yet another top view of the front suspension showing the rearattachment point of the transverse link breaking away from the enginecradle in a further response to the impact event in accordance with thefirst embodiment;

FIG. 22 is a perspective view of a rear side section of the enginecradle showing a lower suspension support structure including an upperflange and a lower flange and a collar configured to receive the rearattachment point of the transverse link in accordance with the firstembodiment;

FIG. 23 is a cross-sectional view of the collar and the rear attachmentpoint of the transverse link showing details of a recess defined withinthe collar, the recess being dimensioned to receive and retain the rearattachment point of the transverse link in accordance with the firstembodiment;

FIG. 24 is another cross-sectional view of the collar and the rearattachment point of the transverse link similar to FIG. 23, showing thetransverse link in a released orientation with the rear attachment pointbeing inserted into the recess of the collar, but being releasable fromthe collar in accordance with the first embodiment;

FIG. 25 is yet another cross-sectional view of the collar and the rearattachment point of the transverse link similar to FIGS. 23 and 24,showing the transverse link in an installed orientation with the rearattachment point being retained within the recess of the collar inaccordance with the first embodiment;

FIG. 26 is an exploded perspective view of the strut and the steeringknuckle of the front suspension showing an upper knuckle breakawaystructure in accordance with a second embodiment;

FIG. 27 is a cross-sectional view of a lower end of the strut takenalong the line 27-27 in FIG. 26, showing details of knuckle attachmentflanges that include the upper knuckle breakaway structure in accordancewith the second embodiment;

FIG. 28 is a perspective view of the strut and the steering knuckle ofthe front suspension fully assembled showing the upper knuckle breakawaystructure in accordance with the second embodiment;

FIG. 29 is a perspective view of the strut and the steering knuckle ofthe front suspension showing the upper knuckle breakaway structure afteran impact event releasing the steering knuckle from the lower end of thestrut in accordance with the second embodiment;

FIG. 30 is an exploded perspective view of the strut and the steeringknuckle of the front suspension showing an upper knuckle breakawaystructure in accordance with a third embodiment;

FIG. 31 is a cross-sectional view of a lower end of the strut takenalong the line 31-31 in FIG. 30, showing details of knuckle attachmentflanges of the strut that include the upper knuckle breakaway structurein accordance with the third embodiment;

FIG. 32 is a perspective view of the strut and the steering knuckle ofthe front suspension fully assembled showing the upper knuckle breakawaystructure in accordance with the third embodiment;

FIG. 33 is a perspective view of the strut and the steering knuckle ofthe front suspension showing the upper knuckle breakaway structure afteran impact event releasing the steering knuckle from the lower end of thestrut in accordance with the third embodiment;

FIG. 34 is an exploded perspective view of the strut and the steeringknuckle of the front suspension showing an upper knuckle breakawaystructure in accordance with a fourth embodiment;

FIG. 35 is a cross-sectional view of an upper end of the steeringknuckle taken along the line 35-35 in FIG. 34, showing details of theupper end of the steering knuckle that includes the upper knucklebreakaway structure in accordance with the fourth embodiment;

FIG. 36 is a perspective view of the strut and the steering knuckle ofthe front suspension fully assembled showing the upper knuckle breakawaystructure in accordance with the fourth embodiment;

FIG. 37 is a perspective view of the strut and the steering knuckle ofthe front suspension showing the upper knuckle breakaway structure afteran impact event releasing the steering knuckle from the lower end of thestrut in accordance with the fourth embodiment;

FIG. 38 is a perspective view of a transverse link shown removed fromthe front suspension, with an outboard side of the transverse linkhaving a lower knuckle breakaway structure in accordance with a fifthembodiment;

FIG. 39 is another perspective view of the transverse link shown in FIG.38 showing the lower knuckle breakaway structure after an impact eventreleasing the ball joint (and the steering knuckle) from the outboardside of the transverse link in accordance with the fifth embodiment;

FIG. 40 is a perspective view of a transverse link shown removed fromthe front suspension, the transverse link having a lower knucklebreakaway structure in accordance with a sixth embodiment;

FIG. 41 is another perspective view of the transverse link shown in FIG.40 showing the lower knuckle breakaway structure after an impact eventreleasing the ball joint (and the steering knuckle) from the outboardside of the transverse link in accordance with the sixth embodiment;

FIG. 42 is an exploded perspective view of the steering knuckle and anoutboard end of the transverse link of the front suspension showing alower knuckle breakaway structure that includes a first cam surface on alower portion of the steering knuckle and a second cam surface on anoutboard side of the transverse link in accordance with a seventhembodiment;

FIG. 43 is a side view of the lower portion of the steering knuckle andthe outboard side of the transverse link showing the first and secondcam surfaces spaced apart from one another in accordance with theseventh embodiment;

FIG. 44 is another side view of the lower end of the steering knuckleand the outboard side of the transverse link showing the first andsecond cam surfaces of the lower knuckle breakaway structure contactingeach other breaking a portion of the ball joint and releasing thesteering knuckle from the transverse link in response to an impact eventin accordance with the seventh embodiment;

FIG. 45 is a perspective view of the rear side section of the enginecradle showing the lower suspension support structure including theupper flange and the lower flange and a collar configured to receive therear attachment point of the transverse link in accordance with aneighth embodiment;

FIG. 46 is a cross-sectional view of the engine cradle and the rearattachment point of the transverse link showing details of transverselink breakaway structure that includes a first cam surface formed on thetransverse link and a second cam surface formed within the recess of theengine cradle in accordance with the eighth embodiment;

FIG. 47 is another cross-sectional view of the engine cradle and therear attachment point of the transverse link similar to FIG. 46, showingthe transverse link beginning to rotate about the rear attachment pointsuch that the first and second cam surfaces begin to contact one anotherin response to an impact event in accordance with the eighth embodiment;

FIG. 48 is yet another cross-sectional view of the engine cradle and therear attachment point of the transverse link similar to FIGS. 46 and 47,showing the transverse link breaking away from the engine cradle inresponse to continued contact between the first and second cam surfacescausing the fastener to break, releasing the transverse link from theengine cradle in accordance with the eighth embodiment; and

FIG. 49 is a perspective view of a transverse link that includes a frontattachment point that includes a collar oriented horizontally inaccordance with a ninth embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Selected embodiments will now be explained with reference to thedrawings. It will be apparent to those skilled in the art from thisdisclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

Referring initially to FIG. 4-10, a vehicle 10 is illustrated inaccordance with a first embodiment. The vehicle 10 is provided with aplurality of wheel releasing features of a front suspension 12 of thevehicle 10 that are configured to release a wheel 14 in response to animpact event such as a small overlap test, such that the wheel 14 movesout of a wheel well 16 of the vehicle 10 during the impact event.

The Insurance Institute for Highway Safety (IIHS) has developed varioustests where vehicles are provided with forward velocity and impactedagainst fixed, rigid barriers, like the rigid barrier B depicted inFIGS. 1-3. In the IIHS offset tests, the conventional vehicle C is aimedat the rigid barrier B such that approximately 25 percent of the frontof the conventional vehicle C impacts the rigid barrier B. In otherwords, as indicated in FIGS. 1-3, only a front corner of theconventional vehicle C impacts the rigid barrier B. This IIHS test isalso known as a frontal offset, narrow offset, or small overlap test. Insuch tests, a front bumper assembly of the conventional vehicle C iseither not impacted, or undergoes only limited contact with the rigidbarrier B during the impact event. Therefore, other structures at thefront of the conventional vehicle C impact the rigid barrier B andabsorb at least some of the kinetic energy associated with the rapiddeceleration of the vehicle C that results from the impact event. Whenthe vehicle C is provided with velocity and impacts the rigid barrier B,the rapid deceleration of the vehicle C transforms the kinetic energyassociated with the mass and velocity of the vehicle C into deformationof the vehicle C and counter movement of the vehicle C. As is wellknown, kinetic energy is a function of mass times velocity. During thesmall offset test, the kinetic energy of the vehicle C is partiallyabsorbed and partially transformed into other forms of kinetic energy,such as rotary motion. It should be understood that the kinetic energyassociated with the forward velocity of the vehicle C (and in thedescription below) is transformed into an impacting force upon impactdue to the rapid deceleration of the vehicle C. Consequently,hereinbelow, the terms impact force and impacting force as used hereincorrespond to the kinetic energy applied to the vehicle 10 during thesmall overlap test (the impact event), as described below with respectto the various embodiments.

The test is represented schematically in FIGS. 1-3. During the impactevent, a variety of structures undergo deformation. This deformation isnot explicitly depicted in FIGS. 2 and 3 with any degree of accuracybecause such deformation varies from conventional vehicle toconventional vehicle, depending upon the overall design of the frontstructure of the conventional vehicle C. Instead, in FIG. 3, theconventional vehicle C is depicted with a generic degree of deformationas a result of the impact event. However, the conventional vehiclestested by the IIHS using the small overlap test have a relativelyconsistent response in that during the impact event with the rigidbarrier B, the rear end R of the conventional vehicle C undergoes somerotation and swings laterally away from the rigid barrier B, asindicated in FIG. 3.

In other words, the forward velocity F_(F) of the conventional vehicle Cas it moves is transformed upon impact with the rigid barrier B. Thevelocity F_(F) results in an equal and opposite reaction force acting onthe vehicle C as the vehicle C suddenly decelerates. It is desirable tomove the vehicle laterally outward from the barrier and avoidunnecessary loading of the dash-wall and/or A-pillar.

The wheel releasing features of the various embodiments describedhereinbelow, when employed in the vehicle 10, are configured such thatduring an impact event, such as a small overlap test, the wheel 14 isconsistently released from the front suspension 12 and moves laterallyout of the wheel well 16 of the vehicle 10, as shown in FIGS. 4, 5 and6. Specifically, in FIG. 4 the vehicle 10 is provided with a forwardvelocity V_(F1) and is subjected to a small overlap test whereapproximately 25 percent of the front of the vehicle aligned with therigid barrier B. In FIG. 5 the vehicle 10 undergoes an initial responseto the impact event of the small overlap test with a front corner of thevehicle impacting the barrier and beginning to undergo deformation.Hence, the forward velocity V_(F1) is reduced to a velocity V_(F2). InFIG. 6, the vehicle 10 undergoes a subsequent response to the impactevent in that one or more of the vehicle releasing features hasfunctioned properly and released the front wheel, such that the frontwheel moves laterally out of a wheel well of the vehicle 10, and theforward velocity V_(F1) is reduced to a velocity V_(F3).

It should be understood from the drawings and the description herein,that during an impact event, such as the small overlap test, thereaction forces experienced by the vehicle 10 as it impacts the rigidbarrier B are significant. These significant reaction forces areexponentially greater than the forces the structures of the vehicle 10undergo during normal operating usage of the vehicle 10. In other words,the impact events referred to herein are intended as destructive tests.Further, the impact events of the small overlap tests are configured toimpact the vehicle 10 such that the rigid barrier B impact the vehicle10 at portions of the vehicle 10 outboard of a lower suspension supportstructure, which includes an engine cradle 46 that is described ingreater detail below.

In the various embodiments described below, the vehicle 10 includes atleast one, or a combination of two or more of a plurality of the wheelreleasing features. The wheel releasing features are included in variousstructural elements that at least partially define the front suspension12 shown in FIGS. 8-10, and described in greater detail below.

A brief description of the vehicle 10 is now provided with specificreference to FIG. 7. The vehicle 10 includes a variety of conventionalelements, such as a front bumper assembly 18, a hood 20, fenders 22, afront side member 24, a dash wall 26, an A-pillar 28 and a sill 30.

The front bumper assembly 18 is a conventional assembly at the front ofthe vehicle 10. The hood 20 conceals an engine compartment and istypically hinged to move between a closed position (FIG. 7) and an openposition (not shown). The fenders 22 are conventional elements thatcover sides of the vehicle 10. As shown in FIG. 7, the depicted fender22 at least partially defines the wheel well 16. The front side member24 is a structural beam-like assembly that extends from the front bumperassembly 18 rearward to the dash wall 26 and further rearward under thepassenger compartment of the vehicle 10. The front side member 24 is aconventional structure that extends in a vehicle longitudinal directionand supports a variety of elements of the vehicle 10, including thefront suspension 12. The dash wall 26 extends laterally fromside-to-side within the vehicle 10 dividing the passenger compartmentfrom the engine compartment. The A-pillar 28 and the sill 30 arestructural elements that at least partially define a front door openingand are rigidly coupled via intermediary structural elements to thefront side member 24.

It should be understood that there are two front side members 24, twoA-pillars 28 and two sills 30 in the vehicle 10. Only one side of thevehicle 10 is shown in FIG. 7 and hence only one of the front sidemembers 24, one of the A-pillars 28 and one of the sills 30 are visible.Description of one of the front side members 24, one of the A-pillars 28and one of the sills 30 applies equally to both sides of the vehicle 10.Since the various portions of the body structure of the vehicle 10 areconventional, further description is omitted for the sake of brevity.

As indicated in FIG. 7, the vehicle 10 also includes a strut tower 32.The strut tower 32 is a conventional structure within the enginecompartment that is rigidly coupled to the front side member 24. Thestrut tower 32 defines at least part of an upper suspension supportstructure of the vehicle 10.

FIGS. 8-10 show the front suspension 12 removed from the front sidemember 24 and removed from the vehicle 10. The front suspension 12includes a plurality of wheel releasing features, such as an upperknuckle breakaway structure 40, a lower knuckle breakaway structure 42and a transverse link breakaway structure 44, which are described ingreater detail below after a description of various other features ofthe front suspension 12. As used herein below, the term breakawaystructure include frangible structures and frangible parts (parts thatbreak or deform allowing release of connections between two separateelements) and also refers to parts or structures where two connectedparts are released from connection with one another without breakage ofeither of the two connected parts.

As shown in FIGS. 8-10, the front suspension 12 includes the enginecradle 46 (a lower suspension support structure as mentioned above),struts 48, steering knuckles 50 and transverse links 52. Since thestruts 48, the steering knuckles 50 and the transverse links 52 areidentical (except that they are symmetrical mirror images of oneanother), description of only one will apply to both. Each of the wheels14 is secured to a corresponding one of the steering knuckles 50 viaconventional bearing structures (not shown) as indicated in FIG. 8. Thearrow D in FIG. 8 indicates a forward longitudinal direction of thevehicle 10.

The engine cradle 46 includes a driver's side engine cradle member 54, apassenger's side engine cradle member 56 and a rear engine cradle member58. The driver's side engine cradle member 54 includes an engine mountattachment portion, but otherwise includes all of the features thepassenger's side engine cradle member 56 (they otherwise symmetricalmirror images of one another). Therefore, description of the driver'sside engine cradle member 54 also applies to the passenger's side enginecradle member 56. The engine cradle 46 also includes a front enginecradle member 59 that extends between the driver's side engine cradlemember 54 and the passenger's side engine cradle member 56. However,since the front engine cradle member 59 is a conventional portion of theengine cradle 46, further description is omitted for the sake ofbrevity.

The rear engine cradle member 58 extends between rearward ends of thedriver's side engine cradle member 54 and the passenger's side enginecradle member 56. The rear engine cradle member 58 supports elements ofthe steering linkage of the front suspension 12. However, since thevarious elements of the steering linkage are conventional components,further description is omitted for the sake of brevity.

The engine cradle 46 also includes body attachment points 60, located atthe four corners of the engine cradle 46, as indicated in FIGS. 8-10.The body attachment points 60 are located for removable attachment viafasteners (not shown) to the underside of the vehicle 10. Morespecifically, the body attachment points 60 attach to the front sidemembers 24 of the vehicle 10. An engine assembly 62 is supported on theengine cradle 46. However, since the engine assembly 62 is aconventional component of the vehicle 10, further description is omittedfor the sake of brevity.

As shown in FIG. 9, a rearward section of the driver's side enginecradle member 54 includes an upper flange 66 and a lower flange 68, witha recess 70 defined between the upper flange 66 and the lower flange 68.The upper flange 66, the lower flange 68 and the recess 70 basicallydefine a lower suspension support structure of the engine cradle 46.More specifically, the transverse link 52 is installed within the recess70 and attached to the driver's side engine cradle member 54 byfasteners that extend through apertures of the upper flange 66 and thelower flange 68. As is indicated in FIG. 9, the transverse link 52 isattached at a first location 72 and a second location 74 of the lowersuspension support structure by fasteners F₁. The first location 72defines a front link attachment point for the transverse link 52 and thesecond location 74 defines a rear link attachment point for thetransverse link 52.

A description of the strut 48 is now provided with specific reference toFIG. 11. The strut 48 includes an upper end 80 and a lower end 82. Asindicated in FIG. 7, the upper end 80 is removably fastened to the struttower 32 (the upper suspension support structure) in a conventionalmanner. The lower end 82 is configured to pivot relative to the upperend 80 in order to facilitate steering of the vehicle 10. The lower end82 includes a pair of knuckle attachment flanges 84, as shown in FIG.11. Each of the knuckle attachment flanges 84 includes a pair ofapertures A that receive the fasteners F₂.

In the first embodiment, the knuckle attachment flanges 84 define theupper knuckle breakaway structure 40. Specifically, the upper knucklebreakaway structure 40 is defined by an area on each of the knuckleattachment flanges 84 adjacent to each of the apertures A. Each of theknuckle breakaway structures 40 are frangible parts that are inclineddownward in a vehicle outboard direction from the apertures A (fastenerreceiving openings). Each of the upper knuckle breakaway structures 40has a first thickness T₁, as indicated in FIG. 12. Each of the knuckleattachment flanges 84 has a second thickness T₂, with the secondthickness T₂ being greater than the first thickness T₁. It should beunderstood from the drawings and the description herein that thethickness T₁ is not necessarily a reduction in thickness as compared toconventional struts. Rather, the thickness T₂ can be increased relativeto conventional struts. In other words, the upper knuckle breakawaystructures 40 are frangible parts. The lower end 82 of the strut 48 istherefore connected to an upper end 88 of the steering knuckle 50 by theupper knuckle breakaway structures 40 which have a predeterminedfrangible part that releases the upper end 88 of the steering knuckle 50from the strut 48 upon application of a prescribed rearward directedforce on at least one of the engine cradle 46 (the lower suspensionsupport structure) and the steering knuckle 50.

Thus, during an impact event as the small overlap test, release of thewheel 14 from the wheel well 16 is facilitated by the breakage of theknuckle attachment flanges 84 at the upper knuckle breakaway structures40. Specifically, FIG. 13 shows the strut 48 attached to the steeringknuckle 50 by the fasteners F₂ during operation of the vehicle 10.During operation of the vehicle 10 (driving), the strut 48 and thesteering knuckle 50 are rigidly secured to one another. During theimpact event, if breakage occurs, the upper knuckle breakaway structures40 deform, releasing the fasteners F₂ and the steering knuckle 50 (alongwith the wheel 14) such that they are free to move away from the strut48 and out of the wheel well 16, as shown in FIG. 14.

As shown in FIG. 15, the steering knuckle 50 includes an upper end 88, alower end 90 and a wheel supporting section 92. The upper end 88 definesan attachment collar that includes a pair of apertures dimensioned toreceive the fasteners F₂ for attachment to the strut 48 in a mannerdescribed above and shown in FIG. 13. The pair of apertures in the upperend 88 of the steering knuckle 50 defines a strut attachment portion. Asshown in FIG. 15, the lower end 90 includes a ball joint receivingaperture 94 dimensioned to receive a ball joint 96 of the transverselink 52. The lower end 90 also includes the lower knuckle breakawaystructure 42. As shown in FIG. 16, the lower knuckle breakaway structure42 has a thickness T₃ that is less than the thickness T₄ of adjacentareas of the lower end 90 of the steering knuckle 50. Put another way,the cross-sectional area of the lower knuckle breakaway structure 42 isless than the cross-sectional area of the adjacent areas of the lowerend 90 of the steering knuckle 50.

The wheel supporting section 92 is provided with a hub and bearingstructure (shown in FIGS. 13 and 14) such that the wheel 14 is coupledto the wheel supporting section 92 in a conventional manner.

During operation of the vehicle 10 (driving), the steering knuckle 50and the transverse link 52 are pivotally secured to one another by theball joint 96. During an impact event such as the small overlap test,since the lower knuckle breakaway structure 42 has a thickness T₃ lessthan the thickness T₄, if breakage occurs, the lower knuckle breakawaystructures 42 breaks, releasing the steering knuckle 50 from thetransverse link 52. Put another way, since the cross-sectional area ofthe lower knuckle breakaway structure 42 is less than thecross-sectional area of the adjacent areas of the lower end 90 of thesteering knuckle 50, if breakage occurs, the lower knuckle breakawaystructures 42 breaks, releasing the steering knuckle 50 from thetransverse link 52. Hence, the steering knuckle 50 (and the wheel 14)are free to move away from the transverse link 52 (and out of the wheelwell 16), as shown in FIG. 17.

The transverse link breakaway structure 44 will now be described withspecific reference to FIGS. 18 thru 25. As shown in FIG. 18, thetransverse link 52 includes a front end 98, a rear end 100, an inboardside 102 and an outboard side 104. The inboard side 102 includes a frontattachment point 110 and a rear attachment point 112. The outboard side104 includes a knuckle attachment point 114, which includes the balljoint 96.

The front attachment point 110 of the transverse link 52 includes acollar 116 that is attached to the engine cradle 46 (the lowersuspension supporting portion) at the first location 72 (the front linkattachment point) by one of the fasteners F₁. The collar 116 is aflexible coupling collar that includes a rubber or polymeric sleeve (notshown) that allows the transverse link 52 undergo vertical oscillationsin response to various driving conditions in a conventional manner.Since such collars are conventional, further description is omitted forthe sake of brevity.

The collar 116 and corresponding one of the fasteners F₁ define a frontconnection structure of the transverse link 52 connecting the front end98 of the transverse link 52 to engine cradle 46 at the first location72, as indicated in FIG. 19. As will be understood in the drawings andthe description herein below, the fastener F₁ at the first location 72is a frangible part that is configured to break in response to theimpact event.

The rear attachment point 112 of the transverse link 52 is coupled tothe engine cradle 46 at the second location 74 (the rear link attachmentpoint) by the other of the fasteners F₁ in a manner that is described ingreater detail below. The knuckle supporting section 114 is attached tothe steering knuckle 50 via the ball joint 96.

As shown in FIG. 18, the rear attachment point 112 of the transverselink 52 includes a crescent shaped attachment portion 120. As indicatedin FIG. 22, a collar 122 is inserted into the recess 70 between theupper flange 66 and the lower flange 68 (the lower suspension supportstructure). As shown in FIGS. 23-25, the collar 122 includes an opening124 that exposes an arcuate shaped recess 126. The opening 124 isdimensioned such that the collar 122 passes into the arcuate shapedrecess 126, as indicated in FIG. 24. Thereafter, the transverse link 52is pivoted into an installed orientation such that the transverse link52 is retained by the collar 122, as shown in FIG. 25. With the collar122 installed to the second location 74 of the engine cradle 46, asshown in FIGS. 19 and 25, the rear attachment point 112 secures thetransverse link 52 in position relative to the engine cradle 46 duringnormal driving operation of the vehicle 10. As is explained furtherbelow, the relationship between the collar 122 and the rear attachmentpoint 112 of the transverse link 52 define a rear link breakawaystructure that allows the transverse link 52 to be released from theengine cradle 46 in response to an impact event, such as the smalloverlap test.

FIG. 19 shows the transverse link 52 installed to the engine cradle 46in the installed orientation with the fastener F₁ at the first location72 retaining the front attachment point 110 of the transverse link 52 tothe engine cradle 46. Further, the collar 122 and the other of thefasteners F₁ retain the rear attachment point 112 of the transverse linkat the second location 74 of the engine cradle 46. As well, although notshown in FIG. 19, the ball joint 96 is installed to the steering knuckle50, retaining the knuckle supporting section 114 of the outboard side104 of the transverse link 52 to the steering knuckle 50.

During normal operation of the vehicle 10, the strut 48 can undergovertical oscillations as a result of uneven road surfaces, the steeringknuckle 50 can pivot about the strut 48 in response to steeringoperations of the vehicle 10 and the outboard side 104 of the transverselink 52 can undergo vertical oscillations as a result of uneven roadsurfaces due to the conventional flexing of the collar 116 and thecollar 122.

During an impact event, such as the small overlap test, the transverselink 52 can breakaway from the engine cradle 46, as described now withreference to FIGS. 20 and 21. Specifically, when an impacting force suchas a prescribed rearward directed force F_(R) acts on one or all of thestrut 48, the steering knuckle 50 and/or the transverse link 52, thefastener F₁ at the first location 72 serves a front link breakawaystructure. Specifically, as indicated in FIG. 20, upon application ofthe prescribed rearward directed force F_(R), the fastener F₁ at thefirst location 72 breaks (the fastener F₁ at the first location 72 is afrangible part). As the impact event progresses, the transverse link 52pivots relative to the second location 74, as shown in FIG. 20. Thus,the transverse link 52 pivots from the installed orientation (FIGS. 19and 25) to the release orientation (FIGS. 20 and 24). The transverselink 52 is no longer retained by the collar 122 and the crescent shapedattachment portion 120 can slip out of the opening 124 of the collar122, as indicated in FIGS. 21 and 23.

During the impact event, the lower knuckle breakaway structure 42, asdescribed above, breaks away allowing the knuckle supporting section 114of the transverse link 52 to be released from the steering knuckle 50.At the same time, it is also possible for the upper knuckle breakawaystructure 40 to release the steering knuckle 50 from the strut 48, asdescribed above. Consequently, the steering knuckle 50 and the wheel 14are released and can exit the wheel well 16 of the vehicle 10.

In the first embodiment described above, the front suspension 12 isdescribed as including all three of the breakaway features, the upperknuckle breakaway structure 40, the lower knuckle breakaway structure 42and the transverse link breakaway structure 44. However, it should beunderstood from the drawings and the description herein that each of thebreakaway features can be used independently or in combination with onlyone of the other two breakaway features. Specifically, the upper knucklebreakaway structure 40 can be employed without one or the other of thelower knuckle breakaway structure 42 and the transverse link breakawaystructure 44. Similarly, the lower knuckle breakaway structure 42 can beemployed without one or the other of the upper knuckle breakawaystructure 40 and the transverse link breakaway structure 44, and thetransverse link breakaway structure 44 can be employed without one orthe other of the upper knuckle breakaway structure 40 and the lowerknuckle breakaway structure 42.

Further, various alternative embodiments of each of the upper knucklebreakaway structure 40, the lower knuckle breakaway structure 42 and thetransverse link breakaway structure 44, are described below. The upperknuckle breakaway structure 40 of the first embodiment can be replacedwith one of the alternative upper knuckle breakaway structureembodiments described below. The lower knuckle breakaway structure 42 ofthe first embodiment can be replaced with one of the alternative lowerknuckle breakaway structure embodiments described below. Further, thetransverse link breakaway structure 44 can be replaced with one of thealternative transverse link breakaway structure embodiments describedbelow.

Second Embodiment

Referring now to FIGS. 26-29, an upper knuckle breakaway structure 140in accordance with a second embodiment will now be explained. In view ofthe similarity between the first and second embodiments, the parts ofthe second embodiment that are identical to the parts of the firstembodiment will be given the same reference numerals as the parts of thefirst embodiment. Moreover, the descriptions of the parts of the secondembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the second embodiment, the strut 48 and the steering knuckle 50 areidentical to the first embodiment, except that the upper knucklebreakaway structures 40 has been eliminated and replaced with the upperknuckle breakaway structures 140. As shown in FIGS. 26-29, the upperknuckle breakaway structures 140 are formed such that they extendupright along the surfaces of the knuckle attachment flanges 84 adjacentto an upright part of the strut 48. Each of the knuckle breakawaystructures 140 is formed with the thickness T₁ which is less than thethickness T₂ of the remainder of the knuckle attachment flanges 84. Asshown in FIG. 29, in response to the impact event, the majority of theknuckle attachment flanges 84 breakaway from the lower end of the strut46.

Third Embodiment

Referring now to FIGS. 30-33, an upper knuckle breakaway structure 140 ain accordance with a third embodiment will now be explained. In view ofthe similarity between the first and third embodiments, the parts of thethird embodiment that are identical to the parts of the first embodimentwill be given the same reference numerals as the parts of the firstembodiment. Moreover, the descriptions of the parts of the thirdembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the third embodiment, the strut 48 and the steering knuckle 50 areidentical to the first embodiment, except that the upper knucklebreakaway structures 40 has been eliminated and replaced with the upperknuckle breakaway structure 140 a. As shown in FIGS. 30-33, the upperknuckle breakaway structures 140 a are formed such that they extendupright along a mid-section of the surfaces of the knuckle attachmentflanges 84. Each of the upper knuckle breakaway structures 140 a isformed with the thickness T₁ which is less than the thickness T₂ of theremainder of the knuckle attachment flanges 84. As shown in FIG. 33, inresponse to the impact event, a portion of the knuckle attachmentflanges 84 breakaway from the lower end of the strut 46.

Fourth Embodiment

Referring now to FIGS. 34-37, an upper knuckle breakaway structure 240in accordance with a fourth embodiment will now be explained. In view ofthe similarity between the first and fourth embodiments, the parts ofthe fourth embodiment that are identical to the parts of the firstembodiment will be given the same reference numerals as the parts of thefirst embodiment. Moreover, the descriptions of the parts of the fourthembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the fourth embodiment, the strut 48 and the steering knuckle 50include all the features described above with respect to the firstembodiment, except that the upper knuckle breakaway structures 40 hasbeen eliminated from the knuckle attachment flanges 84 of the strut 48and replaced with the upper knuckle breakaway structure 240 formed atthe upper end 88 of the steering knuckle 50. As shown in FIGS. 34-37,the upper knuckle breakaway structure 240 is formed at the upper end 88of the steering knuckle 50. The upper knuckle breakaway structure 240has a thickness T_(1A) which is less than the thickness T_(2A) of theremainder of the upper end 88 of the steering knuckle 50. Consequently,the cross-sectional area of the upper knuckle breakaway structure 240 isless than the remainder of the upper end of the steering knuckle 50. Asshown in FIG. 37, in response to the impact event, a portion of theupper end 88 of the steering knuckle 50 remains attached to theattachment flanges 84 of the strut 46.

Fifth Embodiment

Referring now to FIGS. 38-39, a lower knuckle breakaway structure 242 inaccordance with a fifth embodiment will now be explained. In view of thesimilarity between the first and fifth embodiments, the parts of thefifth embodiment that are identical to the parts of the first embodimentwill be given the same reference numerals as the parts of the firstembodiment. Moreover, the descriptions of the parts of the fifthembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the fifth embodiment, the transverse link 52 and the collar 122 arereplaced with a transverse link 252 and collar 122 a. The transverselink 252 includes a rear attachment point 112 a with the conventionalcollar 122 a. Hence, there is no breakaway feature at the rearattachment point 112 a.

The transverse link 252 includes all of the other features of thetransverse link 52 of the first embodiment, such as the front attachmentpoint 110 and knuckle supporting section 114, with the ball joint 96.However, adjacent to the knuckle supporting section 114 of thetransverse link 252, the transverse link 252 is formed with the lowerknuckle breakaway structure 242. The transverse link 252 is providedwith reinforcements (as compared to a conventional transverse link)throughout its overall structure, except at the lower knuckle breakawaystructure 242. Therefore, the lower knuckle breakaway structure 242defines a frangible part. Consequently, as indicated in FIG. 39, inresponse to the impact event, the knuckle supporting section 114 andball joint 96 breakaway from the remainder of the transverse link 252,allowing the steering knuckle (not shown) and the wheel 14 (not shown)to eject from the wheel well 16 of the vehicle 10 during the impactevent.

Sixth Embodiment

Referring now to FIGS. 40-41, a lower knuckle breakaway structure 342 inaccordance with a sixth embodiment will now be explained. In view of thesimilarity between the first and sixth embodiments, the parts of thesixth embodiment that are identical to the parts of the first embodimentwill be given the same reference numerals as the parts of the firstembodiment. Moreover, the descriptions of the parts of the sixthembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the sixth embodiment, the transverse link 52 and the collar 122 arereplaced with a transverse link 352 and the collar 122 a. The transverselink 352 includes the rear attachment point 112 a with the conventionalcollar 122 a. Hence, there is no breakaway feature at the rearattachment point 112 a.

The transverse link 352 includes all of the other features of thetransverse link 52 of the first embodiment, such as the front attachmentpoint 110 and knuckle supporting section 114, with the ball joint 96.However, between the inboard side 102 and the outboard side 104, thetransverse link 352 is formed with the lower knuckle breakaway structure342. The transverse link 352 is provided with reinforcements (ascompared to a conventional transverse link) throughout its overallstructure, except at the lower knuckle breakaway structure 342.Therefore, the lower knuckle breakaway structure 342 defines frangibleparts of the transverse link 352. Consequently, as indicated in FIG. 41,in response to the impact event, the knuckle supporting section 114 andball joint 96 breakaway from the remainder of the transverse link 352,allowing the steering knuckle (not shown) and the wheel 14 (not shown)to eject from the wheel well 16 of the vehicle 10 during the impactevent.

Seventh Embodiment

Referring now to FIGS. 42-44, a lower knuckle breakaway structure 442 inaccordance with a seventh embodiment will now be explained. In view ofthe similarity between the first and seventh embodiments, the parts ofthe seventh embodiment that are identical to the parts of the firstembodiment will be given the same reference numerals as the parts of thefirst embodiment. Moreover, the descriptions of the parts of the seventhembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the seventh embodiment, the lower end 90 of the steering knuckle 50is modified to include a first cam surface C₁. Further, the knucklesupporting section 114 of the transverse link 52 is modified to includea second cam surface C₂. As is well known, the ball joint 96 is astructural member that connects to the steering knuckle 50 and allowsthe steering knuckle 50 to pivot about a vertical axis defined by theball joint 96 such that the steering knuckle 50 can pivot for steeringoperations of the vehicle 10. The first cam surface C₁ and the secondcam surface C₂ are positioned such that during steering operations ofthe vehicle 50, the first cam surface C₁ and the second cam surface C₂do not contact one another, as indicated in FIG. 43. However, inresponse to an impact event where at least one member of the frontsuspension 12 has broken away from the engine cradle 46, the steeringknuckle 50 and the transverse link 52 can undergo relative rotation withrespect to one another such that the first cam surface C₁ and the secondcam surface C₂ contact one another, forcing the transverse link 52 tomove downward and away from the steering knuckle 50, as indicated inFIG. 44. This downward movement of the transverse link 52 can cause theball joint 96 to pull out of the steering knuckle 50 or cause the balljoint 96 to break, as shown in FIG. 44, thereby allowing the steeringknuckle 50 and the wheel 14 (not shown) to eject from the wheel well 16of the vehicle 10 during the impact event.

Eighth Embodiment

Referring now to FIGS. 45-48, a transverse link breakaway structure 344in accordance with an eighth embodiment will now be explained. In viewof the similarity between the first and eighth embodiments, the parts ofthe eighth embodiment that are identical to the parts of the firstembodiment will be given the same reference numerals as the parts of thefirst embodiment. Moreover, the descriptions of the parts of the eighthembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

In the eighth embodiment, the transverse link 52 of the first embodimentis replaced with a transverse link 52 a that includes a full ringstructure at the rear attachment point 112 a and a first cam surface C₃.A conventional collar is installed within the full ring structure of therear attachment point 112 a and the fastener F₁ attaches the transverselink 52 a to the engine cradle 46 at the second location 74. As shown inFIGS. 46-48, the first cam surface C₃ faces the engine cradle 46 withinthe recess 70. Also, in the eighth embodiment, the engine cradle 46 isslightly modified by the inclusion of a second cam surface C₄ formedwithin the recess 70, as is also shown in FIGS. 46-48.

With the transverse link 52 a in an installed orientation depicted inFIG. 46, the first cam surface C₃ and the second cam surface C₄ arespaced apart from one another. However, in response to an impact event,when the fastener F₁ at the first location 72 serves as a frangible partand breaks, the transverse link 52 a begins to pivot about the fastenerF₂ at the second location 74, as indicated in FIG. 47. As is furthershown in FIG. 47, the first cam surface C₃ and the second cam surface C₄begin to contact one another. Further rotation of the transverse link 52a during the impact event causes the first cam surface C₃ and the secondcam surface C₄ to press against one another forcing the rear attachmentpoint 112 a of the transverse link 52 to exert a force on the fastenerF₁ at the second location 74, causing the fastener F₁ at the secondlocation 74 to break (a frangible portion), thereby allowing thetransverse link 52 a to be released from the engine cradle 46.

Ninth Embodiment

Referring now to FIG. 49, a transverse link 52 b in accordance with aninth embodiment will now be explained. In view of the similaritybetween the first and ninth embodiments, the parts of the ninthembodiment that are identical to the parts of the first embodiment willbe given the same reference numerals as the parts of the firstembodiment. Moreover, the descriptions of the parts of the ninthembodiment that are identical to the parts of the first embodiment maybe omitted for the sake of brevity.

The transverse link 52 b includes all of the features of the transverselink 52 of the first embodiment, except that the front attachment point110 of the first embodiment is replaced with a modified front attachmentpoint 110 a. More specifically, the transverse link 52 b includes thefollowing features of the transverse link 52, for example, the front end98, the rear end 100, the inboard side 102, the outboard side 104, therear attachment point 112 with the crescent shaped attachment portion120 and the knuckle supporting section 114 with the ball joint 96.

However, in the first embodiment, the fasteners F₁ at the first location72 and the second location 74 of the engine cradle 46 are verticallyoriented. In the ninth embodiment, the front attachment point 110 a isoriented such that a corresponding fastener is horizontally oriented.Otherwise, the transverse link 52 b is identical to the transverse link52 b of the first embodiment.

The vehicle 10 includes a variety of elements and features areconventional components that are well known in the art. Since theseelements and features are well known in the art, these structures willnot be discussed or illustrated in detail herein. Rather, it will beapparent to those skilled in the art from this disclosure that thecomponents can be any type of structure and/or programming that can beused to carry out the present invention.

General Interpretation of Terms

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Also as used herein to describe theabove embodiment(s), the following directional terms “forward”,“rearward”, “above”, “downward”, “vertical”, “horizontal”, “below” and“transverse” as well as any other similar directional terms refer tothose directions of a vehicle equipped with the vehicle frontsuspension. Accordingly, these terms, as utilized to describe thepresent invention should be interpreted relative to a vehicle equippedwith the vehicle front suspension.

The term “configured” as used herein to describe a component, section orpart of a device includes hardware and/or software that is constructedand/or programmed to carry out the desired function.

The terms of degree such as “substantially”, “about” and “approximately”as used herein mean a reasonable amount of deviation of the modifiedterm such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. For example, the size, shape, location ororientation of the various components can be changed as needed and/ordesired. Components that are shown directly connected or contacting eachother can have intermediate structures disposed between them. Thefunctions of one element can be performed by two, and vice versa. Thestructures and functions of one embodiment can be adopted in anotherembodiment. It is not necessary for all advantages to be present in aparticular embodiment at the same time. Every feature which is uniquefrom the prior art, alone or in combination with other features, alsoshould be considered a separate description of further inventions by theapplicant, including the structural and/or functional concepts embodiedby such features. Thus, the foregoing descriptions of the embodimentsaccording to the present invention are provided for illustration only,and not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

What is claimed is:
 1. A vehicle front suspension comprising; a lowersuspension support structure; a transverse link having an inboard sideand an outboard side, the inboard side attached to the lower suspensionsupport structure; a steering knuckle pivotally coupled to the outboardside of the transverse link; and a lower knuckle breakaway structureformed on the transverse link to release the steering knuckle and anouter portion of the transverse link from an inner portion of thetransverse link upon application of a prescribed rearward directed forceon the vehicle front suspension outboard of the lower suspension supportstructure with the outer portion of the transverse link remainingattached to the steering knuckle.
 2. The vehicle front suspensionaccording to claim 1, wherein the lower knuckle breakaway structureincludes a frangible part formed on the transverse link between theoutboard side of the transverse link and the inboard side of thetransverse link.
 3. The vehicle front suspension according to claim 2,wherein the inboard side of the transverse link includes a frontattachment point and a rear attachment point that are both attached tothe lower suspension support structure, and the frangible part includesa first frangible part located between the outboard side of thetransverse link and the rear attachment point of the transverse link,and a second frangible part located between the front attachment pointof the transverse link and the outboard side of the transverse link. 4.The vehicle front suspension according to claim 1, further comprising anupper suspension support structure; a strut having an upper endconnected to the upper suspension support structure, and a lower endfixedly attached to the steering knuckle by a knuckle attachmentstructure; and an upper knuckle breakaway structure formed on one of theupper end of the steering knuckle and the knuckle attachment structurethat releases the upper end of the steering knuckle from the strut uponapplication of the prescribed rearward force directed to the vehiclefront suspension outboard of the lower suspension support structure. 5.A vehicle front suspension comprising; a lower suspension supportstructure; a transverse link having an inboard side and an outboardside, the inboard side attached to the lower suspension supportstructure; a steering knuckle having a lower end pivotally coupled tothe outboard side of the transverse link, and an upper end; a lowerknuckle breakaway structure formed on the transverse link to release thesteering knuckle and an outer portion of the transverse link from aninner portion of the transverse link upon application of a prescribedrearward directed force on the vehicle front suspension outboard of thelower suspension support structure; an upper suspension supportstructure; a strut having an upper end connected to the upper suspensionsupport structure, and a lower end fixedly attached to the upper end ofthe steering knuckle by a knuckle attachment structure; and an upperknuckle breakaway structure formed on one of the upper end of thesteering knuckle and the knuckle attachment structure to release thesteering knuckle from the knuckle attachment structure upon applicationof the prescribed rearward directed force on the vehicle frontsuspension outboard of the lower suspension support structure.
 6. Thevehicle front suspension according to claim 5, wherein the upper knucklebreakaway structure includes a predetermined frangible part thatreleases the upper end of the steering knuckle from the strut uponapplication of the prescribed rearward directed force on the vehiclefront suspension outboard of the lower suspension support structure. 7.The vehicle front suspension according to claim 6, wherein the upperknuckle breakaway structure includes the frangible part formed at theupper end of the steering knuckle.
 8. The vehicle front suspensionaccording to claim 6, wherein the upper knuckle breakaway structureincludes the frangible part formed on the knuckle attachment structure.9. The vehicle front suspension according to claim 5, wherein the lowerknuckle breakaway structure includes a frangible part formed on thetransverse link between the outboard side of the transverse link and theinboard side of the transverse link.
 10. The vehicle front suspensionaccording to claim 9, wherein the inboard side of the transverse linkincludes a front attachment point and a rear attachment point that areboth attached to the lower suspension support structure, and thefrangible part includes a first frangible part located between theoutboard side of the transverse link and the rear attachment point ofthe transverse link, and a second frangible part located between thefront attachment point of the transverse link and the outboard side ofthe transverse link.